The three codons which result in the termination of polypeptide chain synthesis are

Options

A. UA A,UAG,GUA
B. U A A,UAG,UGA
C. U A A,UGA,U UA
D. UGU, UAG, UGA

Answer

To answer the question regarding the three codons that result in the termination of polypeptide chain synthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Process of Translation**:
- Translation is the process where ribosomes synthesize proteins based on the sequence of codons in mRNA.

2. **Identify the Role of Codons**:
- Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signal the termination of protein synthesis.

3. **Recognize Stop Codons**:
- There are specific codons known as stop codons that signal the end of the polypeptide chain synthesis. These codons do not code for any amino acids.

4. **List the Stop Codons**:
- The three stop codons are:
- UAA (Uracil-Adenine-Adenine)
- UAG (Uracil-Adenine-Guanine)
- UGA (Uracil-Guanine-Adenine)

5. **Explain the Termination Process**:
- When the ribosome encounters any of these stop codons during translation, it does not have a corresponding tRNA to attach. Instead, a protein release factor (RF) binds to the ribosome, prompting the release of the newly synthesized polypeptide chain.

6. **Conclusion**:
- Therefore, the three codons that result in the termination of polypeptide chain synthesis are UAA, UAG, and UGA.

### Final Answer:
The three codons that result in the termination of polypeptide chain synthesis are UAA, UAG, and UGA.

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